When did CME start trading bitcoin?

I'm curious to know, when did the Chicago Mercantile Exchange (CME) actually commence trading in bitcoin? It's an important milestone for the cryptocurrency market, and I'm eager to understand the timeline of this significant event. Was it a recent development, or has it been some time since CME began offering Bitcoin futures contracts? Understanding this information can help me grasp the evolution of the market and its integration into traditional financial institutions.